Silicon Laboratories Si114X User Manual

Si11 4
X
1. Kit Contents
The Si114x Multi-Function Kit contains the following items:
 Si114x Multi-Function Board

Si114x-MFB Quick Start Guide
 2 USB Cables
2. Introduction
The Si114x-MFB is intended as an evaluation and development platform for the Si1143 infrared proximity and
ambient light sensor. The board has two sides which are separate systems that only share communications and
debug connections to the PC. The active side is chosen using the hardware switch S1, shown in Figure 1. When
the switch is in the upward position, the Top-Side is the active side while the Bottom-Side is active when S1 is in
the downward position. As shown on the left side of Figure 1, the main components of the top side of the Si114x
multi-function board (Si114x-MFB) are the Si1143 sensor (U4), the C8051F931 microcontroller (U1), and the
infrared emitters (DS2 through DS4). On this PCB, the infrared emitters used are OSRAM part number SFH 4056.
These emitters have a power rating of 40 mW and a half-angle of 22 degrees. As shown on the right side of
Figure 1, the main components of the bottom side of the Si114x-MFB are the Si1143 sensor (U6), the C8051F931
microcontroller (U5), and the infrared emitter DS5. This emitter is OSRAM part number SFH 4650 and has a power
rating of 45 mW and a half-angle of 15 degrees. Other emitters with different characteristics may also be used,
depending on the specific application requirements.
The example firmware for the top-side of the board is a thumb-scroll implementation that measures the infrared
light energy detected by the Si1143 while each of three infrared emitters are independently activated. The infrared
light from these emitters will be reflected back to the Si1143 by a thumb that is swiped in proximity to the sensor.
The firmware is able to detect different gestures using the infrared sensor, as described in Table 3 on page 10. The
nine LEDs DS8-DS16 will change state to indicate what gesture was recognized. The Si1143's ambient light
sensor (ALS) is also monitored by the firmware. The example firmware is intended to be used in conjunction with
the QuickSense
The example firmware on the bottom-side of the board is a long-range implementation that measures the infrared
light energy detected by the Si1143 while a single infrared emitter is activated. All three of the Si1143's LED drivers
are connected to the one emitter to allow multiple drivers to activate the emitter at the same time in order to send
more current through the emitter than one driver can provide. Driving more current through the emitters can help
achieve longer ranges of detection because the infrared LEDs emit more light with more current. The default
firmware only uses one driver at the default pulse width to drive the LED. The five LEDs DS17-DS21 will change
state to indicate how much infrared light feedback is being measured. The Si1143's ambient light sensor (ALS) is
also monitored by the firmware. The example firmware is intended to be used in conjunction with the
TM
QuickSense
Rev. 0.1 4/11
Downloaded from Elcodis.com electronic components distributor
M - F
ULTI UNCTION
TM
Performance Analysis Tool to provide user feedback.
Performance Analysis Tool to provide user feedback.
Copyright © 2011 by Silicon Laboratories
S i 11 4 x - M F B
K U ' G
I T SER S UIDE
Si114x-MFB